INTRODUCTION TO MACROECONOMICS, THE DATA. The Variables of Interest to Macroeconomists

Transcription

1 INTRODUCTION TO MACROECONOMICS, THE DATA The Variables of Interest to Macroeconomists A stock variable is a variable measurable at one particular time and represents a quantity accumulated in the past (ex: wealth); whereas, A ow variable is measured over an interval of time (ex: income) National Accounts measures the economic activity of a nation. 1

2 Gross Domestic Product (GDP) is one of the national accounts. It is a ow variable and it measures the (before tax) market value of economic output produced within the borders of a country in a year (or quarter) What do we understand from economic output? It is (physical) goods and (intangible) services GDP per capita (person) is obtained when total GDP is divided by the resident population, and it is an important indicator for the well being of an economy 2

3 How is GDP calculated? Production (output) approach: GDP is the summation of the price of goods and services times their amounts Expenditure approach: Things are produced for sale. Thus, the GDP can also be calculated as the total amount of expenditure on these goods and services Income approach: When people buy goods, the money spent on these goods does not leave the economy but it is distributed among the factors of production. It is distributed as salary for workers, rent for capital owners, and the rest stays as corporate income. Therefore, 3

4 GDP is also equal to the total income within the economy As it is seen, the production of goods and services generates an equal value of total income. Hence, GDP is the total income of a country Notice that only if you contribute to the production of the goods in an economy, then you may have an income 4

5 Q: How can we add government to the above model? A: To meet its expenditures, the government should use taxes If governments put taxes on capital or labor, it a ects people s decisions on how much capital to rent or how much to work. This tax lowers people s incentive to work or accumulate capital. The amount of factors of production changes, so does the GDP. This way a government can distort the economy Note that in a simpli ed version of a capitalist economy, we assume government does not involve in production activities 5

6 Q: Suppose some goods are not sold in the year they are produced. How can we calculate GDP in this case? A: We treat those goods as if they are bought by the company itself. The company puts these goods in its inventories to be sold in the coming years. This transaction enters the company s account both as an income and an expenditure. GDP increases. However, if that good is not a durable one (e.g., bread), it is not included in the GDP. In such a case labor earns wage income, but the amount is reduced from producer income 6

7 Q: What is value added way of calculating GDP by production approach? Production of many outputs requires the use of inputs, for instance tires are necessary to produce cars. In calculating GDP, we either count the value of car (final goods approach), or take the value of tires, and combine it the value of car without the tires (value added approach). Thus, value added is the amount by which the value of goods or services are increased in each stage of its production 7

8 In calculating the GDP, three approaches are nearly substitutable (although there can be small statistical discrepancies). But in economic analysis, each gives us di erent insights: If we are interested in how total income is distributed among the factors of production that is, income shares (in GDP) of labor and capital, we may be interested in the Income Approach. If we are interested in questions related to the supply side of the economy (What are the contribution of factors of production to the GDP?), we may use the Production Approach. 8

9 If we are interested in the demand side of the economy (e.g. how much governments and consumers save and how much they consume?), we may refer to the Expenditure Approach (Demand side) 9

10 Expenditure Approach: GDP is usually decomposed into Consumption (C): Private consumption of all (non-)durable goods and services Investment (I): (Non-)residential investment plus change in Inventories Investment does NOT mean individuals purchases of nancial product as we would normally think. Under national accounts buying nancial products is classi ed as saving, NOT investment.) Government Purchases (G): Government s expenditure on goods and services, plus expenditure for infrastruc- 10

11 ture investment or research spending (called government investment,or gross xed capital formation) Net Exports (NX): Exports (X) minus Imports (I) In a closed economy, Exports, Imports,and Net Exports are equal to 0. National Income Accounts Identity Y = C + I + G + NX National Income Accounts Identity in a Closed Economy Y = C + I + G 11

12 A Numerical Example: Suppose there are two producers in an economy: one produces tomatoes and the other produces ketchup. Given the information in Table 1, calculate the GDP of this economy by the approaches outlined above Table 1 Tomate Company ($) Ketchup Company Sales Revenue Productions Costs Wage Payments Input Costs Pro ts

13 Tomate Company ($) Ketchup Company Sales Revenue Productions Costs Wage Payments Input Costs Pro ts (Final Good Approach) GDP=( )+4000=8000$ (Value Added Approach) GDP=(6000-0)+( )=8000$ Expenditure Approach classi es the goods according to by whom expenditure is made (C=8000$) (Income Aproach) GDP=( )+( )=8000$ 13

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15 Note: Housing initially enters as residential investment. Then enters as consumption spending, as people pay rent to live in them. This is expenditure for renters, income for the landlord. If landlord lives in the house by himself, it is treated as he pays rent to itself Case Study: What would be the e ect of the Japanese Earthquake on this country s GDP? In good times, GDP (per capita) is a good to measure of the average well being of the citizens in an economy. However, in bad times, it is not necessarily so 15

16 The quake damaged Japan s existing stock of facilities; hence, Japanese stock of wealth eroded. However, GDP is a ow concept The quake hit an area where considerable production takes place. Hence, GDP would decline due to a possible fall in production But Japanese economy was going through stagnation for decades. Hence, GDP was already below what it would have been under full employment of resources. This is to say there was a large excess supply capacity in Japan. This spare capacity in other parts of the country o set the fall in production in the area hit 16

17 by the quake. Hence, in the short run we do not necessarily observe a decline in GDP Reconstruction costs will be borne by local governments and mostly by the central government, which can collect the money from nancial markets. Thus, national saving goes to government instead of investment. This, in the long run, would decrease the GDP growth rate This public debt will eventually be re ected as higher taxes, leading to decline in the well being of citizens 17

18 Money Supply and Prices: Money Quantity Theory of Suppose 10 identical goods are produced in the economy, and the price of each good is 10 TL. The GDP of this economy is 100 TL Q: How much money do we need in this economy? If the production and sale of the goods occurs at the same point in time, we need 100TL. In this case we say the money in the economy circulates once However, this is not the case in reality. Production of goods in a year does occur in di erent time spans. 18

19 Hence, even a money supply of 20TL in the economy would be enough if there are 5 stages of transactions This gives us the Quantity Theory of Money: If Q is number of goods in the economy, P is the price of goods, M is the money supply, and V is the velocity of money, the following equation always needs to be satis ed Q P = M V 19

20 The Increase in the Money Supply: In ation, Nominal GDP, Real GDP Assume that there are 10 identical good are produced, and the price of each good is 10 TL. The GDP of this economy is 100 TL I assume Central Bank is not independent and the government wants the Central Bank to print 100 TL more. Since the amount of production in an economy is determined by the factors of production (existing labor and capital), the number of goods produced is the same. In this case, by the Quantity Theory of Money, the price of each good should increase to 20 TL 20

21 Since the new money is owned by the government, consumers can now a ord to buy only 5 goods (instead of 10), and the rest of the goods (the remaining 5 goods) are consumed by the government 21

22 We arrive two conclusions 1. In ation, which is %100 here, is a hidden tax (called seigniorage) that enables government to increase its expenditure share without levying direct taxes on consumers 2. Just because GDP increases from 100 TL to 200TL, the economy s well being does not change: there are still 10 goods in the economy to be consumed. Hence, nominal GDP (also called GDP in current prices) is not an appropriate tool to measure the well being of countries. We need create a Quantity Index, which measures the number of goods and services produced in the economy 22

23 Formulas for Calculating Quantity Index We can keep prices xed at a base year (1999 below) and use those prices to weight the quantities produced in different years Real GDP (1999) = (1999 Price of Apples * 1999 Quantity of Apples) + (1999 Price of Computers * 1999 Quantity of Computers) Note that in 1999 Real GDP=Nominal GDP Real GDP (2000) = (1999 Price of Apples * 2000 Quantity of Apples) 23

24 + (1999 Price of Computers * 2000 Quantity of Computers)... This is a quantity index and is called GDP in constant (1999) prices You may compute the same type of index by taking 2000 as the base year. Hence, the level of the Real GDP computed this way is not informative. That is why we index it. In this example we set it equal to 100 in 1999 Changes in quantity indexes give us the Growth in Real GDP 24

25 It can be calculated in a way that Q t = P pb q t P pb q b where b denotes base prices (1999 in the example above) However, there is a problem with this method. As an example, in 2009 computers are cheaper and much more available than in Hence, using their 1999 prices would overestimate the value of computers in year 2009 Accordingly, we develop another quantity index and a stepwise procedure, which we call the Chain-Rule 25

26 Formulas for Calculating Chain-Type Quantity Index The chain-type annual change in Real GDP (Fisher index) takes the geometric mean of two indexes, each measures the change in Real GDP at time t in two adjacent years, one keeps prices xed at t 1, and the other at t Q F t = s P pt 1 q t P pt 1 q t 1 P pt q t P pt q t 1 26

27 Price Indexes Price indexes are used to measure changes in prices. The chain-type price index is s P P Pt F pt q t 1 pt q = P t pt 1 q t 1 P pt 1 q t Consumer Price Index (CPI) (whether it is chain-type or not) measures changes in the price level of consumer goods and services purchased by households 27

28 GDP price de ator (may be called implicit price de ator) gives us the price changes from base year to time t. Unlike CPI, it takes into account all the goods and services in the economy, and it is the ratio nominal gross domestic product to real gross domestic product GDP Deflator F t = P pt q t P pb q t 100 The numerator is the nominal GDP at time t. denominator is the real GDP The 28

29 In practice, the di erence between the de ator and a price index like the Consumer price index (CPI) is often relatively small. On the other hand, governments increasing utilize of price indexes for everything from scal and monetary planning to payments to social program recipients, even small di erences between in ation measures can change budget revenues and expenses by millions or billions of dollars. 29

30 Example: 30

31 Case Study: Turkish GDP and In ation Data Average Yearly Growth Rate Real GDP %4.7 Real GDP per capita %3.4 GDP in billion TL %15 GDP in billion USD %15 Average Yearly Changes in Prices Consumer Price Index %8 GDP De ator %

32 Notes GDP per capita is obtained by dividing total GDP to the resident population, and it is the mean ( rst moment) of the income distribution of individuals. If one is interested in how the total income (GDP) is distributed among citizens, she needs to refer to the variance (second moment) of the income distribution, which is a measure of Income Inequality GDP data is collected quarterly. Annual GDP is the sum of quarterly GDPs 32

33 There is a seasonality e ect on the quarterly GDP data. We do not expect the production to be the same for instance, in winter and summer (for instance heating oil production rises in before the winter heating season). Hence, to calculate GDP growth rate using quarterly data, we should look for 4-quarter growth rates, i.e. compare the Real GDP in any quarter with the corresponding quarter of the previous year. To create an index (which is a level variable) from quarterly data, we should correct the seasonality e ect 33

34 Recessions: Periods of falling Real GDP, severe ones called Depressions Gross National Product (GNP) = GDP + Factor Payments From Abroad - Factor Payments to Abroad Net National Product (NNP) = GNP - Depreciation 34

35 Data Management Turkish Data Go to TCMB web site: choose: English; Data; Statistical Data The US data US Bureau of Economic Analysis: choose: National; National Income and Product Accounts Tables; from a list of All NIPA Tables,... 35

36 Extracts from the TCMB Gross Domestic Product Gayri Safi Yurtici Hasila Final Consumption Expenditure of Resident Households Yerlesik Hanehalklarinin Tuketimi Final Consumption Expenditure of Resident and Non Resident Househo Yerlesik ve Yerlesik Olmayan Hanehalklarinin Yurtici Tuketimi (Less) Final Consumption Expenditure of Non Resident Households on (Eksi) Yerlesik Olmayan Hanehalklarinin Yurtici Tuketimi Final Consumption Expenditure of Resident Households in the Rest of t Yerlesik Hanehalklarinin Yurtdisi Tuketimi Government Final Consumption Expenditure Devletin Nihai Tuketim Harcamalari Compensation of Employees Maas, Ucret Purchases of Goods and Services Mal ve Hizmet Alimlari Gross Fixed Capital Formation Gayri Safi Sabit Sermaye Olusumu Public Sector Kamu Sektoru Machinery Equipment Makine Techizat Construction Insaat Private Sector Ozel Sektor Machinery Equipment Makine Techizat Construction Insaat Change in Stocks Stok Degismeleri Exports of Goods and Services Mal ve Hizmet Ihracati (Less) Imports of Goods and Services (Eksi) Mal ve Hizmet Ithalati 36

37 GSYIH Components: (Cross-Sectional Data) (2010) GSYIH Components: (Time Series Data) 37

38 The importance of seasonal adjustment (see the spikes on the quarterly GDP data shown with the top line) 38

39 Sectoral Decomposition of GDP 39

40 How Economists Think In Economics, we use theoretical models to explain economic processes in the real world. Ex: The model of supply and demand 40

41 Changes in Real GDP are explained in two parts: The (very) long-run (growth) component, and short-run (business cycle) component 41

42 Theory of Economic Growth explains increases in national income decades. Business Cycle Theory explains the uctuations in the data within a period of three months to a couple of years. 42

43 Other Variables of Interest to Macroeconomists Unemployment: Needless to say, it is one of the most important indicators of well being in the economy. If; Number of Employed: E, Number of Unemployed: U, Number of Home Sitting: HS Labor Force: E+U Unemployment Rate: U E+U *100 Labor-Force Participation Rate: E+U E+U+HS *100 43

44 Other important variables Interest Rate (Real Interest Rate= Nominal Interest Rate - In ation) Exchange Rate (A $/TL = 1/A TL/$): Real-Nominal, PPP (Purchasing Power Parity) 44

45 Microeconomic Thinking and Macroeconomic Models Microeconomics is the study of how households and rms make decisions and how these decision makers interact in the marketplace Because economy-wide events arise from the interaction of many households and many rms, macroeconomics and microeconomics are inextricably linked For example, we examine the households decisions regarding how much to consume and how much money to save and the rms decision regarding how much to invest. These individual decisions together form the larger 45

46 macroeconomic picture. The goal of studying these microeconomic decisions in detail is to re ne our understanding of the aggregate economy Sometimes a representative consumer may be all we need to model the economy, but sometimes we use heterogenous agents 46